TY - JOUR A1 - Kricheldorf, H. R. A1 - Meyer, A. A1 - Weidner, Steffen T1 - High Tm Poly(l-lactide)s by Means of Bismuth Catalysts? T2 - Macromolecular Chemistry and Physics N2 - One series of BiSub-catalyzed ring-opening polymerizations (ROPs) is per-formed at 160 °C for 3 days with addition of difunctional cocatalysts to find out, if poly(l-lactide) crystallizes directly from the reaction mixture. An analogous series is performed with monofunctional cocatalysts. High Tm crystal-lites (Tm > 190 °C) are obtained from all bifunctional cocatalysts, but not from all monofunctional ones. It is shown by means of SAXS measurements that the high Tm values are mainly a consequence of a transesterification–homogenization process across the lamellar surfaces resulting in thickness and smoothing of the surfaces. An unusual enthalpy-driven modification of the molecular weight distribution is found for samples that have crystallized during the polymerization. A third series of ROPs is performed at 170 °C for 2 h followed by annealing at 120 °C (2 h) to induce crystallization. Complete transformation of the resulting low Tm crystallites (Tm < 180 °C) into the high Tm crystallites by annealing at 170 °C for 1 d is not achieved, despite variation of the cocatalyst. PB - Wiley KW - Polylactide KW - MALDI-TOF MS KW - Crystallization PY - 2021 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/52277 AN - OPUS4-52277 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-522777 SN - 1022-1352 VL - 222 IS - 8 SP - 19 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany